What's the longest travel fork you have built/would build a hardtail frame around?

Just curious what folks consider the upper limit of travel for a hardtail. That new Pike is giving me a stiffy, but it seems like maybe a silly idea to design a hardtail frame around a 150mm travel fork.

I've actually been thinking a lot about a long travel hard tail.
I think a pretty slack 26" with about 150mm would be awesome to ride.
A buddy of mine just got a Ragley blue pig and set it up with 150mm up front, it's a really fun bike.

I know the PIKE is nice but I'm not sure maximum fork travel is a goal you should be designing around. I've done the all mountain hardtail thing in several different iterations and formed an opinion that geometry trumps fork travel.

I think there's a limit to how much useful travel you can get out of your fork on a hardtail. Unlike a full suspension, which is going to moderate changes in head tube angle during compression (because the rear is also compressing - at least a lot of the time), a hardtail pivots off the rear axle so the head tube angle can change pretty drastically as you go from sagged trail riding (120 mm on a 150 mm travel fork) to full compression (0 mm). If you use a very rough approximation that 25 mm travel length changes your head tube 1 degree, you could have your head tube angle change close to 5 degrees as you use all your travel. That's taking the head tube angle of your 68 degree trail bike up to a twitchy 73 degrees at the exact moment you use all your travel while plowing your front wheel into a rock on a sketchy downhill or while making a bad landing after catching sick air. That's not what I'm looking for in terms of handling variability. I read a similar argument from the BTR guys recently (Support and FAQ | BTR Fabrications).

I've run a 150 mm fork on a hardtail before (On-One 456) and I didn't think it really added to the experience compared to a 120-130 mm fork. I think the whole all mountain hardtail scene has gravitated towards longer travel forks because that's historically what you needed to put on your bike to slacken it out. I think a lot of people would be equally well-served with a shorter travel fork on a frame built for their desired geometry.

If you really want a PIKE I'm sure you could build a frame around it and have lots of fun on it.

If you were looking for comments on frame strength and engineering I just went way off topic...

If you were looking for comments on frame strength and engineering I just went way off topic...

Nope, your comments were right on target. My question is about keeping some semblance of balance between the front and the rear. Somewhere on another forum I read a comment about a long-travel hardtail: "the front was writing checks the rear couldn't cash." I thought that was clever...perhaps that saying has been around for a long time.

My current design for my next frame calls for a 120mm travel 27.5" fork with a 68 degree HA. I'll probably stick pretty close to that. It should be a very capable bike for the type of riding I do.

I would also say there is practical limit to how much travel is really accessible, if necessary. As mentioned, you simply are not going to be taking a HT to the extreme levels that an FS bike is capable of. You will probably get beat to death and bounced into a new frame of mind (if not the rhubarb!) regarding our ambitions long before you run out of 4-5" of fork. Having said that, I'm not sure I would put too fine a point on the geometry change idea either. We are talking an infinitely and rapidly variable state here. Temporary as well. If you fixed your static numbers somewhere in the region where your more extreme situations didn't totally compromise the angles, you would likely never notice.

I think I would place more stock in the former notion than the latter.

Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
- John Hajny, a.k.a. TrailMaker

As mentioned, you simply are not going to be taking a HT to the extreme levels that an FS bike is capable of. You will probably get beat to death and bounced into a new frame of mind (if not the rhubarb!) regarding our ambitions long before you run out of 4-5" of fork.

^makes me *almost* want to take the ht to the park some day. ninja skills, that shinya.

150mm is fine for an aggressive geo ht. i've been sporting 150 & 160mm forks on my ragley bagger for a couple years now; great aggressive trail setup. h/a is around 65*, which puts things in the sweet spot under sag. i'd might go low as 64* if i had the choice. sta is on the steeper side, to help weight the slack front when climbing, and bb is suitably low with the long fork in mind. i run more slow speed compression and a bit higher spring rate than what i would on a dually to keep geometry shifting under control, but as a whole, it's a surprisingly effective and balanced bike.